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Physics Hall · EXH-0005
Why do shadows grow longer and shorter?
The same object can cast a long shadow in the morning and a short one near noon.
Start the experience01
What should you look for?
How did the blocked region change?
- 01A low light made a long shadow
- 02A high light made a short shadow
- 03The shadow pointed away from the light
02
Why does this happen?
Opaque objects block light
A shadow is the region that direct light cannot reach because an object is in the way.
Angle controls length
Low-angle rays travel far across the ground after meeting the object. Steeper rays reach the ground nearby.
This model uses parallel sunlight on flat ground and does not calculate soft shadow edges.
03
Move it before reading the answer
Start with light height. After the first comparison, move the object to see where the blocked region falls.
Science source
Sunshine and ShadowsUCAR Center for Science Education ↗